Police say an elusive sniper who is likely using a high-powered weapon or a hunting rifle has killed another person near Washington D.C. A man pumping gas outside the nation's capital was shot dead Wednesday night, becoming the seventh person to be struck down by a gunman who authorities say has been striking seemingly at random across the Washington area. There have been more than a week of deadly shootings.

Police in Virginia just outside Washington say evidence recovered from this latest shooting leads them to believe it was the work of the same sniper who they say has now struck nine times over the past week. "As a result of the autopsy, ballistic evidence has linked these cases," he said.

Prince William County Police Chief Charles Deane is appealing to the killer to give up, acknowledging authorities have so little information that they have yet to establish even a profile of the suspect.

Investigators do say the sniper is probably an accomplished marksman, because all of the victims were struck with a single shot, apparently fired from a high powered weapon from a distance.

On Wednesday, sources close to the investigation told reporters a hand written message saying "Mr. Policeman, I am God," and scrawled on the back of a tarot card denoting death, was found at the scene of a shooting at a school in nearby Maryland where a 13 year old student was shot and critically injured.

As hundreds of police across the Washington area continue to search for the killer, area residents say the most terrifying aspect of this shooting spree has been its apparent randomness, leaving people to wonder where the sniper might strike next.